Ice, snow and, frost create problems in many areas of construction. For example, when concrete is poured the ground must be thawed and free of snow and frost. In agriculture, planters often plant seeds, bulbs, and the like before the last freeze of the year. In such examples, it is necessary to keep the concrete, soil, and other surfaces free of ice, snow, and frost. In addition, curing concrete requires that the ground, ambient air, and newly poured concrete maintain a temperature between about 50 degrees and about 90 degrees. In industrial applications, outdoor pipes and conduits often require heating or insulation to avoid damage caused by freezing. In residential applications, it is beneficial to keep driveways and walkways clear of snow and ice.
Standard methods for removing and preventing ice, snow, and frost include blowing hot air or water on the surfaces to be thawed, running electric heat trace along surfaces, and/or laying tubing or hoses carrying heated glycol or other fluids along a surface. Unfortunately, such methods are often expensive, time consuming, inefficient, and otherwise problematic.
Ice buildup is particularly problematic in the construction industry. For example, ice and snow may limit the ability to pour concrete, lay roofing material, and the like. In these outdoor construction situations, time and money are frequently lost to delays caused by snow and ice. If delay is unacceptable, the cost to work around the situation may be unreasonable. For example, to pour concrete, the ground must be thawed to a reasonable depth to allow the concrete to adhere to the ground and cure properly. Typically, in order to pour concrete in freezing conditions, earth must be removed to a predetermined depth and replaced with gravel. This process is costly in material and labor.
In addition, it is important to properly cure the concrete for strength once it has been poured. Typically the concrete must cure for about seven days at a temperature within the range of 50 degrees Fahrenheit to 90 degrees Fahrenheit, with 70 degrees Fahrenheit as the optimum temperature. If concrete cures in temperatures below 50 degrees Fahrenheit, the strength and durability of the concrete is greatly reduced. In an outdoor environment where freezing temperatures exist or may exist, it is difficult to maintain adequate curing temperatures.
In roofing and other outdoor construction trades, it may be similarly important to keep work surfaces free of snow, ice, and frost. Additionally, it may be important to maintain specific temperatures for setting, curing, laying, and pouring various construction products including tile, masonry, or the like.
Although the need for a solution to these problems is particularly great in outdoor construction trades, a solution may be similarly beneficial in various residential, industrial, manufacturing, maintenance, and service fields. For example, a residence or place of business with an outdoor canopy, car port, or the like may require such a solution to keep the canopy free of snow and ice in order to prevent damage from the weight of accumulated precipitation or frost. Conventional solutions for keeping driveways, overhangs, and the like clear of snow typically require permanent fixtures that are both costly to install and operate, or small portable devices that do not cover sufficient surface area.
While some solutions are available for construction industries to thaw ground, keep ground thawed, and cure concrete, these solutions are large, expensive to operate and own, time consuming to setup and take down, and complicated. Conventional solutions employ heated air, oil, or fluid delivered to a thawing site by hosing. Typically, the hosing is then covered by a cover such as a tarp or enclosure. Laying and arranging the hosing and cover can be time consuming. Furthermore, heating and circulating the fluid requires significant energy in the form of heaters, pumps, and/or generators.
Currently, few conventional solutions use electricity to produce and conduct heat. Traditionally, this was due to limited circuit designs. Traditional solutions were unable to produce sufficient heat over a sufficient surface area to be practical. The traditional solutions that did exist required special electrical circuits with higher voltages and protected by higher-rated breakers. These special electrical circuits are often unavailable at a construction site. Thus, using standard circuits, conventional solutions are unable to produce sufficient heat over a sufficiently large surface area to be practical. Typically, 143 BTUs are required to melt a pound of ice. Conventional electrically powered solutions are incapable of providing 143 BTUs over a sufficiently large enough area for practical use in the construction industry. Consequently, the construction industry has turned to bulky, expensive, time consuming heated fluid solutions.
A further complication results from the relatively large current drawn through a modular heated cover, as described above. In order to use electricity to provide a solution, significant amounts of current are needed to provide the necessary heat. This high current may pose a safety risk to those working with or around the device. A broken electrical component which conducts electricity may pose a significant risk to a person who comes into contact with the broken component. A traditional solution to provide grounding would be to add a layer of conductive material to the cover and connect a grounding lead to the foil layer. However, adding another layer requires additional raw material and additional work in the manufacturing process, increasing the material costs and the cost of manufacturing the device. In addition, adding another layer increases the weight of the cover and may decrease its flexibility. Since the cover should ideally be mobile and flexible, adding a grounding layer lessens the effectiveness of the cover.
What is needed is a modular heated cover that operates using electricity from standard job site power supplies, is cost effective, portable, reusable, and modular to provide heated coverage for variable size surfaces efficiently and cost effectively. For example, the modular heated cover may comprise a pliable material that can be rolled or folded and transported easily. Furthermore, the modular heated cover would be configured such that two or more modular heated covers can easily be joined to accommodate various surface sizes. Beneficially, such a device would provide directed radiant heat, modularity, weather isolation, temperature insulation, and solar heat absorption. The modular heated cover would maintain a suitable temperature for exposed concrete to cure properly and quickly and efficiently remove ice, snow, and frost from surfaces, as well as penetrate soil and other material to thaw the material to a suitable depth for concrete pours and other construction projects. In addition, the modular heated covers should be configured such that they are less likely to result in harm to an individual working with the covers in the event of an electrical failure in one or more covers. Ideally, the modular heated covers should be grounded in a manner that does not decrease flexibility, increase weight, or require the addition of new layers to the cover.